<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			var name = "张三";
			var age = 20;
			age += 1;// age = age + 1;
			console.log(age)
		</script>
	</head>
	<body>
	</body>
</html>
